Papal Correspondence: Gregory VII's Influence Network, Urban Self-Government, and the Papal Revolution with Jørgen Møller. 2025. Conditional accept at Journal of Historical Political Economy.

This paper analyzes medieval Pope Gregory VII’s role in building coalitions that stimulated urban self-government, a crucial development in the European state-formation process. In the eleventh century, Gregory came to spearhead a reform program that attempted to curb lay control of the Catholic Church, in direct opposition with secular rulers such as German Emperor Henry IV. We argue that Gregory’s campaign – called the “papal revolution” by one prominent scholar – fostered urban associationalism and political autonomy via his ties to local elites. Gregory’s promotion of church reform via his network thereby opened up a wedge that enabled towns to become self-governing. Enlisting new data on Gregory’s correspondence, we provide evidence that receiving more letters from the pope is associated with a higher likelihood of overthrowing the authority of lay-appointed bishops and introducing political self-government.

The Dominican Order and the Printing Press 2025. Accepted for publication at Journal of Historical Political Economy.

The printing press was arguably one of the most important pre-modern innovations. Why did some European cities adopt it and not others? I argue that the Dominican monastic order played a key role in explaining the diffusion of the printing press, as the technology was helpful in pursuing the order's spiritual and missionary goals. The article documents that cities with a Dominican monastery prior to the invention of the printing press, were more than twice as likely to adopt the press following its invention. 

What Can We Learn about the Effects of Democracy Using Cross-National Data? 2024. Online first at American Political Science Review, 1-10.

More than 1100 studies have been published that examine the effects of democracy using cross-national data since 2000. This short article examines whether these analyses have sufficient statistical power to detect an effect of democracy. Using Monte Carlo simulation and examining consensus effects previously reported in the literature, the article finds that studies are only powered to detect very strong effects of democracy when examining countries over time. This raises questions about what sort of relationships can be analyzed using cross-national data.    

Parliamentary Constraints and Long-term Development: Evidence from the Duchy of Württemberg 2024. American Journal of Political Science, 68(1): 24-41.

Did parliamentary constraints foster economic activity or was activity the cause of constraints? This article addresses the first part of this question by examining the long-term effects of belonging to the Duchy of Württemberg wherein the parliament placed considerable checks on the various Dukes from 1495 to 1796. I use a geographic natural experiment and compare areas just inside of the Duchy with adjacent areas outside of it. Economically similar prior to 1495, areas within the Duchy had a higher degree of urbanization and commercialization in the subsequent period. I provide further evidence that this difference reflects three mechanisms: local representation in parliament, improved local public goods provision, and attraction of upper tail human capital.  

Broadstreet blog post

Pre-Modern Institutions and Later Support for Autocrats in Democratic Elections 2024. Firstview at British Journal of Political Science: 1-18.

A history of local inclusive institutions is correlated with higher levels of democracy today. However, it is unclear whether this reflects an effect of historical institutions on democracy or a prior common cause. Using a geographic natural experiment, this letter demonstrates that a historical experience with inclusive institutions is related to less support for autocratic parties in nineteenth and twentieth-century Germany. This suggests that electoral support for political parties that seek to subvert democracy can be influenced by pre-modern institutions even when they were destroyed prior to the introduction of democracy. 

The Christianization of War: How the Church Reform Movement Incentivized Armsbearing Elites to Conquer the Holy Land with Jørgen Møller. 2024. Journal of Historical Political Economy, 4(2): 189-219.

The crusades that began around AD 1100 are among the most staggering examples of how religious ideas can be reinterpreted to justify warfare. How can we explain this “Christianization” of war and how can we explain its resonance in medieval Europe? This paper argues that the eleventh-century church reform movement, made possible by the ninth- and tenth-century Carolingian state collapse, incentivized its lay supporters to go on crusade as part of the struggle to spread its religious program. This relationship was strongest for the First Crusade; it weakened for subsequent crusades as the new and revolutionary ideas about penitential warfare became widely accepted following the surprising (and bloody) conquest of Jerusalem in 1099. Using data on the location of crusaders between 1096 and 1192—and instrumenting for proximity to the church reform movement using distance from its place of origin (Cluny Abbey in Bourgogne)—we provide evidence in support of this argument.

Why Was Central Europe Characterized by Political Fragmentation? 2024. Journal of Historical Political Economy, 4(1): 89-115.

Political fragmentation and resulting continuous warfare were important parts of European history, and it has been linked to innovation, economic growth, regime change, and state formation. Scholars have long debated the importance of the decade-long interregnum in the Roman Empire of the German Nation for this development. This article documents that the death of Emperor Frederick II in 1250 and the ensuing demise of the Hohenstaufen dynasty marked a divergence in central European history. Prior to 1250, the level of political fragmentation was similar in the Empire and other European states; after 1250, imperial areas saw a marked increase in local political autonomy compared to other areas. This difference in political fragmentation persisted until the modern period. Vol. 4: No. 1, pp 89-115 

Early-Adulthood Economic Experiences and the Formation of Democratic Support with David Andersen and Suthan Krishnarajan. 2023. British Journal of Political Science, 53(2): 387-406.

Do economic experiences early in life affect regime support later in life? Effects of recent economic performance on regime support are extensively studied, but lasting effects of individual-level economic experiences across the lifespan remain unexplored. We argue that in democracies and autocracies alike, economic experiences in early adulthood (i.e., age 18‒28) are wired into people’s memories and become important cues for their democratic support later in life. Having lived in a well-performing economy in a democracy increases democratic support throughout most of people’s lives, whereas having lived in a well-performing economy in an autocracy decreases democratic support throughout most of people’s lives. Using extensive survey data on support for democracy covering 97 countries from 1994 to 2015, we find support for these propositions, demonstrating that economic experiences in early adulthood, conditional on the regime in place at the time, have strong, robust, and lasting effects on democratic support.

The Diffusion of Urban Medieval Representation: The Dominican Order as an Engine of Regime Change 2021. Perspectives on Politics 19(3): 723-738.

How do representative institutions diffuse from one polity to another? I investigate the effect of the Dominican order on the transition from autocratic to representative city government in medieval Europe. I argue that the order’s practices of representation diffused to local lay politics because of the persistent interaction between Dominican monks and urban elites. Using a difference-in-difference design, I offer evidence that the presence of Dominican houses fostered the development of representative city government. My findings highlight the important role that religious institutions can play in the diffusion of political institutions and principles. 

Broadstreet blog post; OUP blog post;

The Collapse of State Power, the Cluniac Reform Movement, and the Origins of Urban Self-Government in Medieval Europe with Jørgen Møller. 2021. International Organization 75(1): 204-223.

Several generations of scholarship have identified the medieval development of urban self-government as crucial for European patterns of state formation. However, extant theories, emphasizing structural factors such as initial endowments and warfare, do little to explain the initial emergence of institutions of urban self-government before CE 1200 or why similar institutions did not emerge outside of Europe. We argue that a large-scale collapse of public authority in the ninth and tenth centuries allowed a bottom-up reform movement in West Francia (the Cluniac movement), directed by clergy but with popular backing, to push for ecclesiastical autonomy and asceticism in the eleventh and twelfth centuries. These social realignments, facilitated by new norms about ecclesiastical office holding, stimulated the urban associationalism that led to the initial emergence of autonomous town councils. Using a panel data set of 643 towns in the period between 800 and 1800, we show that medieval towns were substantially more likely to establish autonomous town councils in the period between 1000 and 1200 if they were situated in the vicinity of Cluniac monasteries. These findings are corroborated by regressions that use distance from Cluny—the movement's place of origin—to instrument for proximity to Cluniac monasteries. 

American purpose blog post; Broadstreet blog post; OUP blog post;

State First? A Disaggregation and Empirical Interrogation with David Andersen. 2022. British Journal of Political Science 52(1): 408-415. 

This letter is the first to systematically scrutinize the multifaceted claim that a strong state promotes democratic development. It analyzes new Varieties of Democracy data from 1789 to 2015 to specify and examine eight different versions of this ‘state-first’ argument in analyses that span the entire era of modern democracy. The authors document that high levels of bureaucratic quality at the time of the first democratic transition and during democratic spells are positively associated with democratic survival and deepening. By contrast, state capacity has no robust effects on democratic survival or deepening and does not condition the impact of bureaucratic quality. These findings underline the importance of particular features of a strong state as well as the importance of a disaggregated approach. They imply that democratic development is better aided by strengthening the impartiality of bureaucratic organizations than by building capacity for territorial control. 

Review of "Sacred Foundations: The Religious and Medieval Roots of the European State By Anna M. Grzymała-Busse. Princeton: Princeton University Press.  2024. Politics and Religion 17(1): 181-182. 

Review of "The Deep Roots of Modern Democracy" by John Gerring, Brendan Apfeld, Tore Wig, and Andreas Forø Tollefsen. Cambridge: Cambridge University Press.  2023. Perspectives on Politics 21(2): 752-753.